After experiencing less than outright success at Le Mans with the Cadillac Le Monstre Cunningham in 1950, Chrysler powered Cunningham C2R in 1951, similarly powered C4R in 1952 and C5R in 1953 Briggs Cunningham decided that three short comings of the previous designs had to be addressed.
His next new project the C6R, had to be smaller, lighter and right hand drive to optimise weight distribution on a circuit with predominantly right hand corners.
The C6R was also originally intended to be powered by a race bred 340 hp 4.5 litre / 274 cui Ferrari V12 motor of the type more commonly found in a Ferrari 375MM of the type he had run at Le Mans in 1954 for Phil Walters and John Fitch.
Responsibility of the design for the body of the C6R was handed over Herbert “Bud” Unger who had worked on the bodies of the Cunningham C4R and C5R Cunningham’s as a metal worker.
In correspondence with me, about the design, Mr Unger said; “The engineers wanted maximum air flow to the brakes front and rear…” These were 13 inch air cooled drum brakes, prone to fading when hot. “I made the front air intake as large as possible and also extra air intakes on both sides beside the main grille air intake.
Next, I tapered the side of the body in from the front fenders all the way back to the rear fenders and by large air scoops to get maximum ram air into both rear brakes.”
By the time the car appeared at Sebring in 1956 with it’s unpainted aluminium body, crafted by “a man form Europe that was an expert with the (English) wheel.
Briggs, for reasons unknown, compromised the original design criteria by fitting a modified 3 litre Indy 500 engine running on petrol instead of the usual alcohol brew.
Le Patron shared the driving at Sebring with John Gordon Bennett and they retired from the race on the 54th lap after the clutch disintegrated.
When the C6R appeared at Le Mans the body had some alterations including a single smaller front intake and a D-Type Jaguar like headrest and rear fin and the car ran over the weekend with the rear brake cooling intakes in open and blanked off configurations.
During the course of it’s second race Briggs and Sherwood Johnson found the C6R started loosing gears and it retired from 13th place after 18 hours after the engine had enough of pushing the car round in forth, top, gear only.
Briggs Cunningham raced the car one more time in 1955 at Road America where the Offy motor again expired for good.
The car did not run again until 1957 by which time a 3.8 litre 6 cylinder Jaguar six cylinder motor had been fitted.
Briggs raced the car on four occasions with a best known result of 9th at Lime Rock in June 1957.
The car was permanently retired to Briggs Cunningham’s collection thereafter which has since become part of the Collier Collection. It is seen here at recent Goodwood Festival of Speed meetings.
My thanks to Mr Unger, Cunningham Motorsport Historian Lawrence W. Berman, Paul Kierstein from the photo archive and Sondre Kvipt in Norway who facilitated my correspondence with Mr Unger. Thanks also to Herbert at The Nostalgia Forum who brought up the subject of the C6R’s blanked off rear air intakes.
Thanks for joining me on this “Smaller, Lighter, RHD” edition of “Gettin’ A L’il Psycho On Tyres” I hope you will join me for Ferrari Friday tomorrow. Don’t forget to come back now !